CALGARY – Athabasca Oil Corp. (TSX:ATH) shares dropped on Monday as the company sought to allay investor concerns surrounding the $1.23-billion sale of its Dover oilsands stake to its Chinese partner

The stock closed down nearly seven per cent at about $6.41 on the Toronto Stock Exchange.

A report in the Financial Post over the weekend suggested PetroChina is trying to lower the amount owed to Athabasca because it is unhappy with the quality of the oilsands assets. Further clouding matters are recent reports out of China that a handful of PetroChina officials with ties to Canada are under investigation.

Athabasca released a terse statement Monday providing “clarification” on the sale its 40 per cent stake in the Dover oilsands project to a unit of state-owned PetroChina, saying the two companies are working to close the deal, as set out in their agreement, and that the company would update investors on any material developments

The company had been aiming to receive the proceeds from the sale by around mid-year so it could develop other assets in its portfolio.

A 2009 joint-venture deal covering the MacKay River and Dover projects included an exit strategy of sorts for the Canadian company. In 2012, PetroChina took full control of the MacKay River project without any significant glitches.

But, the process for Dover has been anything but easy. Months before the most recent speculation, regulatory approval for Dover — a prerequisite for the sale to PetroChina — had been held up by a legal challenge from a nearby First Nation.